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documentation.suse.com / SUSE Enterprise Storage 7.1 Documentation / Administration and Operations Guide / Cluster Operation / Backup and restore
Applies to SUSE Enterprise Storage 7.1

15 Backup and restore

This chapter explains which parts of the Ceph cluster you should back up in order to be able to restore its functionality.

15.1 Back Up Cluster Configuration and Data

15.1.1 Back up ceph-salt configuration

Export the cluster configuration. Find more information in Section 7.2.14, “Exporting cluster configurations”.

15.1.2 Back up Ceph configuration

Back up the /etc/ceph directory. It contains crucial cluster configuration. For example, you will need a backup of /etc/ceph when you need to replace the Admin Node.

15.1.3 Back up Salt configuration

You need to back up the /etc/salt/ directory. It contains the Salt configuration files, for example the Salt Master key and accepted client keys.

The Salt files are not strictly required for backing up the Admin Node, but make redeploying the Salt cluster easier. If there is no backup of these files, the Salt minions need to be registered again at the new Admin Node.

Note: Security of the Salt Master Private Key

Make sure that the backup of the Salt Master private key is stored in a safe location. The Salt Master key can be used to manipulate all cluster nodes.

15.1.4 Back up custom configurations

  • Prometheus data and customization.

  • Grafana customization.

  • Manual changes to the iSCSI configuration.

  • Ceph keys.

  • CRUSH Map and CRUSH rules. Save the decompiled CRUSH Map including CRUSH rules into crushmap-backup.txt by running the following command:

    cephuser@adm > ceph osd getcrushmap | crushtool -d - -o crushmap-backup.txt
  • Samba Gateway configuration. If you are using a single gateway, backup /etc/samba/smb.conf. If you are using an HA setup, also back up the CTDB and Pacemaker configuration files. Refer to Chapter 24, Export Ceph data via Samba for details on what configuration is used by Samba Gateways.

  • NFS Ganesha configuration. Only needed when using an HA setup. Refer to Chapter 25, NFS Ganesha for details on what configuration is used by NFS Ganesha.

15.2 Restoring a Ceph node

The procedure to recover a node from backup is to reinstall the node, replace its configuration files, and then re-orchestrate the cluster so that the replacement node is re-added.

If you need to redeploy the Admin Node, refer to Section 13.5, “Moving the Salt Master to a new node”.

For minions, it is usually easier to simply rebuild and redeploy.

  1. Re-install the node. Find more information in Chapter 5, Installing and configuring SUSE Linux Enterprise Server

  2. Install Salt Find more information in Chapter 6, Deploying Salt

  3. After restoring the /etc/salt directory from a backup, enable and restart applicable Salt services, for example:

    root@master # systemctl enable salt-master
    root@master # systemctl start salt-master
    root@master # systemctl enable salt-minion
    root@master # systemctl start salt-minion
  4. Remove the public master key for the old Salt Master node from all the minions.

    root@master # rm /etc/salt/pki/minion/minion_master.pub
    root@master # systemctl restart salt-minion
  5. Restore anything that was local to the Admin Node.

  6. Import the cluster configuration from the previously exported JSON file. Refer to Section 7.2.14, “Exporting cluster configurations” for more details.

  7. Apply the imported cluster configuration:

    root@master # ceph-salt apply